Check Power of Two (2) using C program

/*C program to check number is power or 2 or not.*/
 
#include <stdio.h>
 
int main()
{
    int num;
    int tempNum,flag;
     
    printf("Enter an integer number: ");
    scanf("%d",&num);
     
    tempNum=num;
    flag=0;
    /*check power of two*/
    while(tempNum!=1)
    {
        if(tempNum%2!=0){
            flag=1;
            break;
        }
        tempNum=tempNum/2;
    }
  
    if(flag==0)
        printf("%d is a number that is the power of 2.",num);
    else
        printf("%d is not the power of 2.",num);
      
    return 0;
}

Using User Define Function

/*C program to check number is power or 2 or not.*/
 
#include <stdio.h>
 
/*function definition*/
int isPowerOf2(int number)
{
    while(number!=1)
    {
        if(number%2!=0)
            return 0;
        number=number/2;
    }
    return 1;
}
 
int main()
{
    int num;
    printf("Enter an integer number: ");
    scanf("%d",&num);
 
    if(isPowerOf2(num))
        printf("%d is a number that is the power of 2.",num);
    else
        printf("%d is not the power of 2.",num);
     
    return 0;
}

Output:

First Run:
Enter an integer number: 32
32 is a number that is the power of 2.

Second Run:
Enter an integer number: 36
36 is not the power of 2.